> Unfortunately, the subset of PCI devices that have GPEs associated> with them is quite limited and the other devices have to rely on> the GPEs associated with their upstream bridges and, possibly, the> root bridge to generate ACPI wake-up events in response to PMEs from> them. Moreover, ACPI devices tend to share wake-up GPEs, in which> cases it makes sense to install an ACPI notify handler for only one> of them and "bind" the other devices to it. Furthermore, ACPI-based> PCI hotplug also uses ACPI notify handlers that in general may> conflict with the PM notify handlers, unless this issue is> specifically taken care of.

I'm not sure this approach is correct - for instance, from a Dell system: